Tablet computing is a compelling and growing technology. Using a pen-like stylus to interact with your laptop opens up a whole new aspect to using a computer, in general, and programming a computer, in particular. TabletPC Windows programming is powerful yet simple. Bob Reselman gets you up and running with the basics of TabletPC in no time at all.

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Tablet computing is a compelling and
growing technology. Using a pen-like stylus to interact with your laptop opens up a
whole new aspect to using a computer, in general, and programming a computer, in
particular. Granted, years ago tablet computing was not ready for prime time.
Laptop hardware was not as developed as was necessary to support the technology
and the basic software had a way to go to be viable. The joke about using a pen
to write the word peg and having the computer understand the input as
the word jog is very relevant and very frustrating. However, that was
then and this is now. Today, using and programming TabletPC is surprisingly
simple. Microsoft has built reliable handwriting recognition and high-resolution
stylus management into Windows XP TabletPC Edition and in all versions of
Windows Vista. In addition, the .NET TabletPC API takes away all the underlying
difficulty that used to be the case for programming for TabletPC.

Given all the improvements that have come to pass over the last few years,
TabletPC is a technology that will take hold in years to come—particularly
in medicine and aeronautics.

In this article I’ll show you the basics that you need to know for
programming WinForms on a TabletPC. I will cover basic hardware and operating
system considerations unique to tablet computing. Then I’ll talk about Ink
and Strokes, which are the building blocks of TabletPC graphics. Finally,
I’ll show you how to write a simple TabletPC program that does handwriting
recognition and then explain the more advanced features of the sample program
that enables you to save and retrieve Ink-based data.

NOTE

I assume that you have some WinForm/.NET programming experience and that you
have a reading knowledge of C#.

Understanding the TabletPC environment

Whereas in standard personal computing input is limited to the keyboard and
mouse, in TabletPC computing, the primary input device is the stylus, with the
keyboard and mouse playing secondary roles. As expected, you use the stylus to
"write" on the surface of the TabletPC screen.

There are two types of interaction that can happen between stylus and screen: resistive and electromagnetic. A resistive interaction is one
in which the TabletPC’s screen is pressure-sensitive only to the touch of
the stylus. Therefore, the stylus must be in contact with the computer screen
before any interaction can take place. Electromagnetic interaction, on the other
hand, is one in which the TabletPC screen senses the presence of the stylus once
the device comes within proximity. No contact between stylus and screen is
required for interaction to take place. Thus, in an electromagnetic interaction
you see the stylus cursor move across the screen at the location of the stylus,
despite the fact that there is no contact between stylus and screen. However,
there is no "writing magic." For writing to take place, contact must
occur between stylus and screen. Whether a stylus is resistive or
electromagnetic is dependent upon the TabletPC hardware. Most modern TabletPC
laptops use electromagnetic technology for stylus/screen interaction.